In conventional brakes, a primary braking force or actuator force is imparted by an actuator to the actuating element such that the brake pad is pressed against the brake disk. When the brake pad comes into contact with the brake disk, a tangential force is generated because the rotating brake disk drags the brake pad with it. This tangential force is diverted by the lever to the actuating element and acts as a secondary braking force or auxiliary force that presses the brake pad against the brake disk to an additional degree.
A disadvantage of this known brake is that, at the time at which the brake pad comes into contact with the brake disk, the tangential force is generated abruptly, which abruptly boosts the primary braking force imparted by the actuator. If a small braking force is to be imparted, a situation may arise in which the actuator initially moves the brake pad toward the brake disk, the brake pad then comes into engagement with the brake disk, the tangential force is diverted by the lever and then boosts the brake force to a value considerably higher than the desired braking force. The actuator must thereupon move the brake pad away from the brake disk, the tangential force decreases suddenly and the braking force imparted by the brake pad to the brake disk falls abruptly to a value considerably below the desired braking force. This cycle repeats and leads to a fluctuating braking force.
In other words, the function that relates the braking force (x axis) imparted by the brake pad to the brake disk to the primary braking force imparted by the actuator to the actuating element (y axis) has a discontinuity. If the braking force is to be linearly increased, the actuator must at a certain time apply an abruptly changing primary force to the actuating element. In the region of the discontinuity, it is only possible with a great degree of difficulty to regulate the brake such that the comfort of a vehicle equipped with such a brake is not impaired.